Compressing air heats it up. Cool air is denser and contains more oxygen. This means hot air contains less oxygen. Your engine needs oxygen to burn petrol.This means that while turbocharging or supercharging definitely adds power, overall potential power could in theory be lost to this. Almost all forced induction cars come with an intercooler of some sort to counteract this.An intercooler is a sort of air-to-air radiator. Air from the turbo is passed through a series of fins and air passing over the surface of it cools the air inside back down before it goes into the engine.As with most things on your car, the factory part will have been specified for a certain power level. While this will usually be adequate for a non-tuned engine, adequate isn't what car tuning is all about!Fitting an uprated intercooler will unlock more power from your existing engine and future proof your car for upgrades to come.On many engines you will see a power increase just from upgrading to a bigger/better